This is the only cast-iron intake that came on a production vehicle that will mount a Holley 4 barrel carburetor without an adapter plate. No longer available new, this unique manifold carries casting number 3872783. It is actually a 2 barrel manifold internally with a 4 barrel plenum area. Recommended when rules allow Holley 4 barrel carb without an adapter plate. These “Holley Type” cast iron intake manifold are hard to find and our supply is limited.
Stage 1 Ported: A ported intake manifold that is modified as much as possible through the plenum area and the port opening. These manifold receive 5 hours of CNC machining followed by hand porting and shot blasting to put some “texture” back into the ports. Nothing on the outside of the manifold is altered. Typical performance gain is 15 to 25 horsepower over a stock manifold.
Fully CNC Ported: The Fully CNC Ported manifolds receive 7 hours of CNC machining, which includes the machining of four 2 1/2″ access holes in the manifold. The access holes allow us to modify 100% of the manifold. After the CNC work, the manifolds are hand ported, shot blasted to put come texture back in the ported and the 4 access holes are sealed. The result is typically a 30 to 45 horsepower gain. This is the best cast iron manifold available.